Percentage calculator



May 19, s. DEUTCH I PERCENTAGE CALCULATOR Filed F919. 5. 1,940

Patented May 19, 1942 UNTED STATES PATENT OFFICE PERCENTAGE vCALCULATOR Samuel Deutch, New York, N. Y.

Application February 5, 1940, Serial No. 317,443

1 Claim. (Cl. 235-69) This invention is a calculator to be used for quickly determining percentages based upon certain .or known mathematical ratios, and While it is capable of use in a variety of business enterprises, it is of particular value in quickly determining percentages in favor of or against a bettor in hand or open book operations at race tracks.

In race track operations where open or book betting is practice-d, the maker of the book lists the names of the various horses participating in a race with the odds posted opposite to such names. vor the maker of the book to the `disadvantage of the better. In other words, the odds posted are -greater in his favor thanthe abilities of the horse justify. The percentage of odds upon all horses participating in a race should as nearly as possible approximate 100 in order to give the bettor a fair chance to win. In accordance with the odds laid by the bookmaker it frequently happens that the total percentages of odds for all horses participating inthe race exceeds 100 and may approximate 130% to 150%. This total, obviously, is unfair to the better, and the shortness of time or the absence of means or mathematical ability to summarize the percentages, prevents the bettor from approximating the sum total of the percentages. The present invention is a calculator for the 'purpose ofA immediately determining the percentages based upon the odds posted, to enable the operator thereof to determine quickly, easily and Without involved mathematical calculation on his part, the total percentages, at the odds or fractions posted, of all horses participating in a race.

The invention will be best understood with reference to the accompanying drawing, where- Figure 1 is a front elevation, parts broken away, of a calculator constructed in accordance with the invention;

Figure 2 is a longitudinal sectional View taken through the body of the calculator;

vFigure 3 is a transverse sectional view; and

Figure 4 is a perspective view of one of the calculator slides removed from the casing.

The calculator of my invention includes avrelatively small thin casing, of light Weight and preferably of a size and shape as to enable the same to be readily carried in the pocket. The casing includes a backing or tray 5 with a cover 6 to telescopi-cally t snugly thereon. Any desired means will be employed for securing the CTX It frequently occurs that the odds fatray and cover rmly together. Arranged within the tray and co-terminus therewith is a frame 'I having a plurality of slots 8 arranged in spaced parallel relation and extending longitudinally of the frame. The frame is relatively shallow and when properly seated Within the tray affords a shallow space 9 between itself and the other undersuriace of the cover 6.. These parts may be formed of light inexpensive metal, or, if `desired, may be made of any other material suited for the purposes.

The frame 1 is provided with a plurality of slide members IU, each of which is provided at its opposite ends with detents or prongs Il to slidably engage within the slots 8 of the frame. The slides are somewhat shorter than the frame member so as to permit of considerable movement thereon. Each slide is provided at one of its longitudinal edges with spaced notches or teeth l2 to be engaged by the point of a stylus or pencil to move the slide relative to the frame. It will be observed that the notches l2 overlie the frame 'l so that a stylus engaged in the notches will rest and bear upon the said frame. The cover or top member 6 is provided with a plurality of longitudinally disposed slots I3, so disposed as to overlie the notched edges of the underlying slide members l0. The slots I3 extend from a point near the top of the frame to approximately the mid-way point, and it is obvious that the pencil or stylus point may be inserted through the slots I3 and engaged with one of the notches or teeth lf2 in an underlying slide in order that the latter may be moved longitudinally of the frame.

The cover 6 is provided approximately midway its length `with a series of sight openings I4, so positioned as to `directly overlie the slides thereunder. The slide members i0 are preferably formed of strips of metal possessing a degreeY of resiliency and are bowed longitudinally as shown in Figures 2 and 4. By this construction, frictional contact between the slide members and the underface of the cover occurs throughout approximately the length of the slides, which contact tends to maintain the slides against accidental or casual movement. Thevface of the cover 6 is provided with indicationsof the usual odds or fractional quantities placed upon horses participating in a race, which indications are positioned 'adjacent to the slots t3 and immediately opposite the notches l2 visible through the slots. The face o'f each slide member has imprinted thereon in relatively bold figures the percentage values corresponding to the fractional quantities or odds appearing inthe column with which each slide is associated. The location of these percentage figures upon the slides is such that when the slide is moved downwardly by the stylus from a notch appearing adjacent to one of the odds gures appearing on the cover, until further movement is arrested by engagement of the stylus with the bottom of the slot I3, the opening I4 directly below the column of figures will display the percentage equivalent of such odds or fractional quantity. Figure 4 of the drawing shows the slide member for that column of odds gures at the right of Figure 1. The ligure 50 at the bottom of the column on the slide indicates the percentage equivalent of an even money or a 1-1 wager, and this figure will appear in the opening I4 if the stylus is inserted in the notch opposite the indication 1-1 and moved downwardly to the bottom of the slot. The next ligure upwards on the slide is the percentage equivalent of a 1-2 wager, while the remaining figures indicate the percentage equivalents corresponding to the other odds figures or fractional values appearing throughout such column. If the stylus is engaged with the notch at the top of `the column opposite the odds 1-9, and is moved to its downward limit, the percentage figure appearing in the sight opening I4 will be 90, which indicates that the maker of the book has a 90% chance in his favor. The remaining columns of figures appearing on the face of the cover show the other odds as customarily employed in racing operations, and it will be understood that the underlying corresponding slide members will have imprinted thereon for observation in the sight openings I4, the percentage equivalent of the Various odds or fractional values.

It has been estimated that in order for a bettor to stand a fair chance to win, the sum total of the percentages of odds upon all horses in the race should be approximately 100. If the sum total of such percentages exceeds this ligure, then the maker of the book is at an advantage and this advantage increases as the percentage total increases. In Figure 1 of the drawing, the slides for three horses in a race have been operated with the following odds and showing true percentages:

In other words, with the three horses in the race at the odds stated, the bettor will stand approximately an even chance of Winning from the maker of the book. Upon seeing the odds posted upon the board, the operator of the calculator moves the slides corresponding to the odds appearing and then totals the percentage figures appearing in the sight openings. Fractions of percent may be ignored. If the sum total of these percentages exceeds 100, he will know immediately that the chances of success are in favor of the bookmaker. In this event, the bettor withholds his wager and if suiiicient number of wagerers withhold their bets, the maker of the book will be compelled to revise the odds in order to induce the bets. As an illustration of how this might operate, the following example of the odds on a race involving seven horses is given, showing the percentage of success in favor of the bookmaker, and other figures illustrating how such odds would likely be changed in order to attract the bettor.

From the foregoing it is apparent that I have devised a calculator which will be extremely helpful to the betting public in open book operations in determining the chances of success in wagers upon odds posted by the maker of the book. The operator of the device, with the use of a pencil point or stylus, may immediately determine the percentage for or against his success, upon any and all of the listed horses, and the sum total of the percentage figures may be readily determined by extremely simple arithmetic calculation.

The calculator may be made of light inexpensive metal or may be made of cardboard or other materials if desired. The construction of the device is such that it may be manufactured and marketed at extremely low cost, and is of such size as to be conveniently carried in the pocket. The frictional contact between the bowed slides and the underace of the cover is suicient to maintain the slides against casual or accidental movement whatever position the calculator may assume. By arranging the frame in such manner that a stylus or pencil point inserted in a notch engages the surface of the inherently resilient frame, the frame serves as a bearing for the point to facilitate ready movement of the slide and the slight depression of the frame, due to the application and operation of the stylus, diminishes the frictional contact between the bowed slide and the cover to free the latter for movement. This minimizes the likelihood of distortion or breakage of the notch edges or the longitudinal slots in instances where the body and frame are constructed of more o1` less imsy material.

Having thus described my invention what I claim as new and useful is:

In a calculator, a body including a trayrand a cover, a frame of equal length and breadth with said tray arranged within the latter and spaced from the cover and tray, said frame having longitudinal slots therein, said cover having slots therein parallel with the frame slots but out of register therewith, slides arranged upon said frame, detents on said slides engaged in said frame slots, the ends of said detents spaced from the bottom of said tray, said slides being resilient and bowed longitudinally so as to normally frictionally contact the underface oi' said cover, said slides having openings at their edges underlying said cover slots and disposed above portions of said frame, the inherent resiliency ol said frame enabling the latter to recede from the underface of said cover when a stylus is projected through said openings and into depressing contact with the said frame to thus diminish the frictional contact between the slides and the said cover.

SAMUEL DEUTCH. 

